Symptoms of Low Refrigerant Levels in Cooling Systems

When the temperature climbs outdoors, homeowners often seek refuge indoors to beat the heat and humidity. But if your home feels more like an oven than a sanctuary from the sweltering weather, your air conditioner may need attention.

If your AC is struggling to keep things cool, it could be due to a refrigerant leak. HVAC.com explores common symptoms of low refrigerant levels in an AC unit and the steps you should take to get your system back up and running again.

What’s the Role of Refrigerant in a Cooling System?

Think of refrigerant as a sponge for heat. It circulates through the indoor evaporator coil and extracts warm air inside your home, turning it from a liquid to a gas in the process. It releases that heat outside before returning to its liquid state and allowing the cycle to continue, keeping your home cool.

Without proper refrigerant levels, air conditioners struggle to maintain ideal temperatures, leading to comfort issues, high utility bills, and increased wear and tear as the system runs longer cycles.

Causes of Refrigerant Leaks

Refrigerant leaks are most commonly caused by damage to the refrigerant lines, typically caused by wear and tear, improper installation, or loose connections. Additionally, corrosion of the evaporator coil can cause leaks.

Accidental damage from outdoor lawn equipment such as weed eaters or neglecting maintenance can also exacerbate the problem, underscoring the importance of regular inspections to prevent issues from escalating.

7 Common Symptoms of Low Refrigerant

1. Decreased Cooling: If your air conditioner isn’t cooling your home as effectively as it used to, low refrigerant levels could be to blame.
2. Warm Air Blowing from Vents: When refrigerant levels are low, the air coming from your vents may feel warmer than usual, even when the system is running. Inspecting the airflow from your vents is an easy step to perform to check for potential issues.
3. Frozen Evaporator Coil: Low refrigerant levels can also cause the evaporator coil to freeze over, restricting airflow and reducing cooling capacity. You may notice a water puddle near your indoor HVAC system, indicating a potential frozen evaporator coil.
4. Increased Energy Bills: Did you do a double-take on your recent utility bill? A sudden spike in your energy bills without a corresponding increase in system usage could indicate that your system is working harder due to low refrigerant levels.
5. Hissing or Bubbling Noises: Keep an ear out for hissing or bubbling noises near the indoor or outdoor unit of your HVAC system, which occurs due to the high-pressure release of refrigerant gas escaping from the system.
6. Visible Refrigerant Leaks: In some cases, you may notice visible leaks or stains around the refrigerant lines or components of your air conditioning system. Do not attempt to make a repair or clean the refrigerant yourself, as it is dangerous to handle. Only certified technicians are qualified to handle refrigerants.
7. Frequent Cycling: If your air conditioner is turning on and off more frequently than usual (short cycling), it could be a sign of low refrigerant levels affecting the system’s ability to maintain consistent cooling.

Should You Recharge or Replace Your Air Conditioner if It Leaks Refrigerant?

If your system still uses R-22 refrigerant, you should highly consider upgrading to a new unit that uses R-410A. HVAC manufacturers stopped using R-22 in new systems in 2010 as part of the complete phase out of the refrigerant due to its ozone-depleting qualities. Currently, only recycled R-22 refrigerant is available, causing prices to skyrocket. Recharging a system that uses R-22 can cost $200 to $600.

R-22’s replacement, R-410A, is found in the majority of today’s cooling systems. Although it’s also in the early stages of being phased out because of its high global warming potential if it leaks, it still remains affordable and readily available as manufacturers develop new, more environmentally friendly options.